In the 1960s, governmental genetics researcher David Banner tries to improve human DNA. His supervisor, Colonel Thaddeus "Thunderbolt" Ross, forbids human experimentation, so David experiments on himself. His wife, Edith, soon gives birth to their son, Bruce Banner. David realizes Bruce inherited his mutant DNA and attempts to find a cure. After discovering his experiments, Ross shuts down David's research; David rigs Desert Base's gamma reactor to explode as revenge. Believing he is dangerous, David tries to kill Bruce but accidentally murders Edith when she gets between them; the trauma makes Bruce suppress his early childhood memories. Ross arrests and sends David to a mental hospital, putting the four-year-old Bruce into foster care. Mrs. Krenzler adopts him, and Bruce assumes the surname, growing up believing his birth parents are dead.